SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bac95e469534bc92729a9520c3fdd2c1775639e38481f7add6b620d6a788b83e' 
  AND token = 'ewUV5E4GaRwjDFTnnWdZzreC/jXd2PBNi63gPMJNp7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}